How Long can Alcohol be Detected in a Breathalyzer?
A breathalyzer can detect alcohol as long as it is in your system. How much and what you drink along with your weight affects how intoxicated you are. Figure one drink per hour leaves the body. If you drank a 12 pack of beer you are looking at 12 hours of it being in the system. That means a breath test will pick it up in that period.
1 Additional Answer
It all depends on how many drinks a person has. It takes a very healthy liver to process one drink in only an hour. I think if your going to drink and plan to drive home get there early, and give yourself at least 6 or 7 hours to drive home.